272 UNITED STATES GEOLOGICAL SURVEY— TEUTIAUY FLORA. 



ilg. 7 is soiDPwiiat restored. It is. upon the specimen, split in two along the 

 niidril), and the nervation, as well as that of" lig. 9, is mostly obsolete; the 

 point of the veins being so indistinct that; it; is not possible to .see if they 

 curve under the teeth or enter them. The nervation ot'lig. 8 is more distinct, 

 and of the same character as that of fig. 6 of the former species. The shape 

 of tlie fragmentary leaf of fig. 9, and its border divisions, are comparable to 

 those of Quercus Ilicoides, Ileer (Fl. Tert. lielv , iii, p 180, \A: cli, fig. 25); 

 by the flat, apparently cartilaginous, border; it is also related to /. dryan- 

 drcefolia., Sap. (Et., 1, 2, p. 89, pi. 10, fig. 8), which, like lliis species, has 

 smaller, narrower, linear leaves, either with shorter teeth or with large ones, 

 deeply cut, in long spiniform divisions. The nervation is, however, different. 

 Habitat. — Sage Creek, Montana, with Sequoia Ileerii; this one repre- 

 sented in numerous fragments {Dr. F. V. Hayden). 



R H A M N E ^ . 



This family of plants does not occupy an important place in the present 

 North American flora. It is there represented b}' a few .species of shrubs of 

 the genera Paliurus, Zlzyphus, Berdiemia, Rhninnus, Ceaiwthu» ; the three 

 first of which by one species each, Rliamnus hy three in the Atlantic and 

 as many in the Pacific slope, and Ceanothus l)y four Eastern and eighteen 

 Californian species. Two other genera, Coluhrina and Gouatiia^ have each 

 one species in Florida. In the geological times, the species of this grouj) 

 apjjear in comparatively larger numbers, except, however, in Ceanothus; for 

 European authors have described nine IMiocene species of Paliurus, eight- 

 een oi Zizyphus of the same period, with three; Eocene species. Berdiemia 

 has three, Rkamnus thirty-four, Miocene, mostly in the lower divisions of 

 the formation, with one Eocene, and Ceanothus only one. As this family at 

 the present epoch is generally distributed in tropical regions, Zizyphus in 

 Asia and Africa, Khamnus in South America, the numerous species of the 

 Miocene serve as records of the climate. From the Eocene of Mississippi, 

 one species of Ceanothus and one of Rharnnus have been published (Trans. 

 Amer. Philos. Soc, vol. xiii, pp. 419, 420); the Cretaceous flora of the Dakota 

 group has one leaf referred to Paliurus. Those descrilied here seem to 

 indicate in our Tertiary a distribution corresponding to thai of the Rhamnece 

 in the European Miocene. Besides these, one Zizyplius and one Ceanothus 

 are recognized in the Pliocene flora of California. 



